- Pre-printed parts by Mendel Parts (Original Mendel): http://reprap.org/wiki/Mendel_Build_Manual
- Elektronic board: http://reprap.org/wiki/Megatronics_2.0
- Running Marlin firmware: https://github.com/rickvanderzwet/Marlin/
Some handy pages to get started:
March 9, 2018
[rick@rvdzwet-wasus Marlin]$ lsb_release -a LSB Version: :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:... Distributor ID: Fedora Description: Fedora release 27 (Twenty Seven) Release: 27 Codename: TwentySeven [rick@rvdzwet-wasus ~]$ arduino java.awt.HeadlessException at java.awt.SplashScreen.getSplashScreen(SplashScreen.java:117) at processing.app.Base.<init>(Base.java:206) at processing.app.Base.main(Base.java:135) [rick@rvdzwet-wasus ~]$ rpm -qa | grep openjdk java-1.8.0-openjdk-headless-184.108.40.206-5.b14.fc27.x86_64 [rick@rvdzwet-wasus ~]$ sudo dnf install java-1.8.0-openjdk [rick@rvdzwet-wasus ~]$ arduino java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it. at java.awt.SplashScreen.getSplashScreen(SplashScreen.java:117) at processing.app.Base.<init>(Base.java:206) at processing.app.Base.main(Base.java:135) /usr/share/arduino/hardware/arduino/avr/boards.txt ############################################################## megatronics.name=Megatronics megatronics.upload.tool=avrdude megatronics.upload.protocol=wiring megatronics.upload.maximum_size=258048 megatronics.upload.speed=115200 megatronics.bootloader.low_fuses=0xFF megatronics.bootloader.high_fuses=0xDA megatronics.bootloader.extended_fuses=0xF5 megatronics.bootloader.file=stk500v2/stk500boot_v2_mega2560.hex megatronics.bootloader.unlock_bits=0x3F megatronics.bootloader.lock_bits=0x0F megatronics.build.mcu=atmega2560 megatronics.build.board=AVR_MEGATRONICS megatronics.build.f_cpu=16000000L megatronics.build.core=arduino megatronics.build.variant=mega
Difference between thermistor and thermocouple: https://electronics.stackexchange.com/questions/24975/differences-between-thermistors-and-thermocouples
March 10, 2018
Dead PSU Controller
start echo: External Reset Marlin 1.1.8 echo: Last Updated: 2017-12-25 12:00 | Author: (none, default config) echo:Compiled: Mar 10 2018 echo: Free Memory: 5418 PlannerBufferBytes: 1264 echo:Hardcoded Default Settings Loaded echo: G21 ; Units in mm echo:Filament settings: Disabled echo: M200 D3.00 echo: M200 D0 echo:Steps per unit: echo: M92 X80.00 Y80.00 Z4000.00 E500.00 echo:Maximum feedrates (units/s): echo: M203 X300.00 Y300.00 Z5.00 E25.00 echo:Maximum Acceleration (units/s2): echo: M201 X3000 Y3000 Z100 E10000 echo:Acceleration (units/s2): P<print_accel> R<retract_accel> T<travel_accel> echo: M204 P3000.00 R3000.00 T3000.00 echo:Advanced: S<min_feedrate> T<min_travel_feedrate> B<min_segment_time_us> X<max_xy_jerk> Z<max_z_jerk> E<max_e_jerk> echo: M205 S0.00 T0.00 B20000 X10.00 Y10.00 Z0.30 E5.00 echo:Home offset: echo: M206 X0.00 Y0.00 Z0.00 echo:PID settings: echo: M301 P22.20 I1.08 D114.00 ok T:18.87 /0.00 B:23.38 /0.00 @:0 B@:0
Listing of g-code (Gcode) found at: http://marlinfw.org/meta/gcode/
Bed temperature reported using M105 was incorrect since power supply was faulty causing interference on the IC measuring the temperature. Replaced power supply, all happy again.
Dead PSU heatbed
My resistor bed consist of of 4 x 2R2 (WH10) in series resulting in 9 Ohm, PSU does not like this low load conditions or is simply broken which would make my 2nd dead power supply. The new PSU is only 12V which is not heating up properly. According to Ohm's law (I = V/R or R = V/I or V = IR) and my resistor rating i get 1.3A, which in result would yield only (W = VI) 15.6W heating power, not sufficient since my total resistor capacity is 40W. Which would give me W = VI combined with V = IR becomes W = IRI. W=40, R=9, makes I = 2A. Which in result would require V to be 40W / 2A = 20V. To fix this I will need to change the resistor bed layout. Instead of 4 in series. Put two in parralel and next two pairs in serie.
Stepper motors turns the wrong way
The orientation of the stepper motors does not match the standard one in the Marlin firmware. Since I rather keep the firmware configuration as vanilla as possible reversing the connectors on the board is the easiest way to make it all compatible again.
In order to print a working nozzle is required, with proper temperature settings for this nozzle (185C) and feed rates (500). One way is to use manual codes to allow debugging:
- First set the temperature of the nozzle M104 S185.
- Ensure the extruder coordinates are relative avoiding math additions of feeding new PLA. Issue M83.
- Wait till the temperature is right, by checking it manually M105 a few times.
- Set the extruder head to a free location (G0 X0 Y0 Z150)
- Set feedrate by 500 using G0 F500.
- Feeding start by G0 E100 (repeatedly).
Check for clean flow, in this case it should not stick to the nozzle and look clean and smooth. Some observations:
- Smoke is bad, because it means the PLA is boiling inside.
- Too cold will cause the PLA too stall while feeding.
Feedrate (F factor) will determine overall printing speed of the printer, sometimes setting the temperature a bit higher could potentially make a faster feedrate, yet this really depends on the nozzle construction.
X Stepper not working
The Pololu A4988 stepper driver did not delivering enough current to X stepper motor to function properly. I replaced it with an unused one, yet I do believe I could use the potentiometer to add some power too it. Believed to be caused by the bearings which are a bit dirty after a 4 years requiring the motor work a little harder.
Y end-stop not working
Auto-homing (G28 Z) did not work, Y stop was not set correctly. Simple problem of broken cabling because of broken DIY connector, replaced with proper molex connector. Working like a charm again.
While busy adjust end-stop allowing filament garbage bin to be reachable.
- Debugging: https://www.simplify3d.com/support/print-quality-troubleshooting/
- Tooling: https://fedoraproject.org/wiki/SIGs/3DPrinting
Tried pronterface and ultimaker cura, both without luck. Printer is detected yet died because heaterbed heats up too slow, causing the Marlin firmware to trigger a failsafe error.
March 10, 2018
Heatbed too slow
Tried hacking longer timeouts, yet no luck. Current heatbed cannot generate enough heat for 2 degrees per 60 seconds above 45 degrees. How-ever when constantly on it will roughly stabilize at 65 degrees, so no firmware controlled heatbed for now.
Cura does not print
First of all the Mendel printer is not supported in firmware, manually adding the printer will failed to print my test properly. It simply does not move the X-axis, no debugging options found for following gcode, abandoning choice.
First result printrun & slic3r
Well this works, the overall result lookt oke-ish. Dimentions alright and some small warping, which is fixable by tunables. Also bed leveling is not correct.
March 14, 2018
Stepper motors dead
Stepper motors are not working properly, seems to stall. Also Pololu A4988 stepper driver seems to be getting really hot, not configurered correctly. First statictics for SY42STH47-1684B
Step angle: 1.8° Number of phase: 2 Rated voltage: 2.8 V Rated current: 1.68 A Holding torque: 4.4 kg/cm
March 30, 2018
New steppers arrived
New stepper DRV8825 motors has arrived. First reduced rating to roughly 1A per instructions of Claire from Pololu. I do not like the new 1/32 stepping setting, not many people are using it and it seems rather useless on my low-resolution printer. Hence the jumpers below the stepper drivers are removed, only M2 (3th jumper from the left) is left.
Demo printing again
The demostration print accedentally printed using setting from an other printer. The result how-ever looks much smoother, which seems rather odd since the nozzle is completely different.
Z-axis Step size issues
The demostration print as perfect diamentions on X and Y (20mm), yet the Z axis is not correct. Instead of 5mm it is roughly 3mm. Some tweaking on STEP sizes needs te be done using M92 Z6666.66 as starting point. Turns out Marlin firmware by default does not allow saving to EEPROM using M500
#define EEPROM_SETTINGS needs to be uncommented in file:Configuration.h to get it to work.
4 April, 2018
Filament is inserted too slowly, causing the tracks to be too small. Changed from E500 (default) to E800.
Heatbed to slow
After my modification my heat bed is still very slow, causing the printer to go into emergency reset state, because it thinks the temperature sensor is broken. Searching for alternatives I found the use of Peltier Element. I have a few old TEC12706AJ around, as such I think I can give it a shot..
Printer result not so good
Time to start doing some testing http://reprap.org/wiki/Calibration
April 11, 2023
Time has passed, time to revive the project. With the help of other enthusiasts I have re-printed most of the parts in much higher quality. And did a re-assemble of the complete printer with same new additional features:
- E3D v6 nozzle design
- GT2 timing belts for X and Y axis, with metal gears.
- Heated prusa PCB printbed, with cork underlayment and glass mirror top.
- Raprap Discount Smart Controller mounted on megatronics board
- Marlin 2.x firmware
It's a Frankenstein design for sure, but it work (sort of), after some endless tuning (and manual bed levelling) I now able to print objects. 5 years of slicer design made things a whole bunch more easy. PrusaSlicer is a absolute big help over here.
Things currently causing issues:
- Feeder is no good. Lots of grinding and pressure just seems 'off'.
- Existing programs to edit models files are limited available for personal use. For example SketchUp, DesignSpark retrict usage to only their tooling. And Solid Edge, Solidworks are to my knowledge not available for free for personal use. I have some luck with Art Of Illusion. How-ever I personally only like those which are open source. Sticking to LibreCAD, FreeCAD or OpenSCAD.
Since RepRap prefer AIO as designer. I had no luck with getting the stable release to work at an Windows 11 platform. How-ever the nightly build works just fine. Also do note the plugin manager is broken in the nightly build a fix is provided by the author.